Kerrison rongeurs are utilized in spinal surgery to remove bone and tissue and thereby gain access to the spinal canal. Kerrison rongeurs typically comprise a stationary shaft and a cutting slide that is longitudinally slidable relative to the stationary shaft. At the distal end of the cutting slide is a cutting edge which engages a foot plate that is located at the distal end of the stationary shaft. The cutting edge on the cutting slide and the foot plate on the stationary shaft are commonly referred to as the “cutting jaws”. When a Kerrison rongeur is in use, the surgeon places the bone to be cut, such as the leading edge of the lamina of a vertebrae, within the cutting jaws. The surgeon then squeezes the handle of the rongeur which causes the cutting edge of the cutting slide to be advanced through that portion of bone to reach the foot plate and thereby amputating that portion of bone.
During use of a Kerrison rongeur, blood, tissue and bone can accumulate between the stationary shaft and cutting slide. Since the accumulated materials are often difficult to remove, subsequent uses of an improperly cleaned rongeur can result in cross-contamination events. For this reason, attempts have been made to design a Kerrison rongeur that can be quickly and easily, fully or partially disassembled to provide access to the spaces between the stationary shaft and cutting slide where the accumulated materials reside.
U.S. Pat. No. 6,126,674 to Janzen describes a Kerrison rongeur that can be completely disassembled by means of a pin that can slide out over a slot in a trigger thereby releasing the slide. A drawback of the device is that the parts can become lost during cleaning and sterilization. U.S. Pat. No. 6,723,103 to Edwards describes a Kerrison rongeur that when held in a retracted position by means of an elastic member, a gap is formed between the cutting slide and the stationary shaft to provide access there between. However, this gap is not sufficiently wide to allow unfettered access between the slide and shaft by brushes for thorough cleaning. Further, the distal portions of the cutting side and stationary shaft remain in contact where the accumulated materials cannot be easily cleaned out. U.S. Pat. No. 5,961,531 to Weber and German Patent Application No. DE102009006689 to Heinemann each describe a convertible rongeur that opens up in an alligator-jaw-like manner which exposes the surfaces between the cutting slide and the stationary shaft. Although the converted devices remain assembled in a single piece since the cutting slides are left dangling in an open position, the devices tend to occupy more space in the sterilization chamber than they do in the closed position and increase the likelihood of the cutting slide becoming bent or otherwise damaged.